1. Field of the Invention
This invention pertains to mounting assemblies for antennas and more particularly to a window mount assembly for a CB antenna which provides increased signal transmission quality and permits a conventional vertical CB mobile antenna to be interchangeably used as a CB base station antenna.
2. Prior Art
Window mounts for TV antennas are known. Such mounts include an outwardly biased window bracket for clamping the mounting to the sides of a window. Such an antenna assembly for use with television signals is currently being manufactured by RMS Electronics, Inc., the assignee hereof, as their model # WC-50.
Recently, there has been an increased interest in CB radios and their associated apparatus. While the principal application of CBs is in mobile vehicles such as automobiles and trucks, they also serve extensively at fixed base stations as in houses, garages, apartments, etc. Many people, for example, have CBs in both their cars and their residences.
When considering the best location for mounting of the base station antenna, it should be kept in mind that the same rules apply to CB antennas that apply to other antennas operated in the HF band, i.e., they should be mounted as high and as in the clear as possible. This would dictate that the optimum location for the antenna is on the roof of the structure in which the base station is situated. Unfortunately, however, housing regulations of apartment high rise buildings often prohibit outdoor roof top antennas.
Ideally, a vertical antenna should be installed over a planar ground so that advantage may be taken of low angle radiation which results in increased signal transmission strength. On cars, for example, the center of the automobile roof is generally the best place for mounting. When, however, practical considerations make it impossible to mount the vertical antenna over a planar ground, the practice has been to employ a plurality of ground plane elements which collectively serve as an artificial metallic ground for the antenna and provide low angle radiation of the transmitted signal regardless of the antenna's height above actual ground. As an example of a vertical antenna employing ground plane elements see, for example, U.S. Pat. No. 3,665,478.
U.S. Pat. No. 2,724,053, which discloses a window mounted antenna for TV reception, is particularly ill-suited for use with a vertical CB antenna. Thus, according to that patent, if the antenna were positioned to receive vertically polarized TV signal waves, it would be substantially flush with the window thereby resulting in a drastic reduction in the strength of the received signal. Moreover, no provision is made for varying the horizontal orientation of the antenna once it has been vertically positioned. Further, even if such provision were made, this alone would be ineffective to vary the field strength in any given direction (assuming the antenna was employed for transmitting), inasmuch as the field strength of the signal transmitted from a vertical antenna is uniform in all horizontal directions. Thus, some other means must be developed for providing the increased directional field strength necessary for effective signal transmission from a window mounted vertical CB antenna.